The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Motorized vehicles may include a powertrain (e.g., an engine, an electric motor and/or a combination thereof) that produces drive torque that is transmitted through a transmission to wheels of the vehicle. Operation of the powertrain and transmission may be regulated by one or more control modules. The control modules may include self-diagnostic capabilities to detect faults that may affect engine performance, emissions, braking, and other onboard systems of the vehicle. Specifically, the control modules may include diagnostic programs or instructions that may detect faults with driver interface devices (e.g., accelerator pedal), sensors (e.g., manifold temperature sensor), and actuators (e.g., throttle valve) of the vehicle.
When a fault is detected for one of the driver interface devices, sensors, or actuators, the control modules may generate a diagnostic trouble code that identifies the specific fault detected. The control modules may save the diagnostic trouble code in memory. The control modules may also store and update a fault status of each stored diagnostic trouble code. The fault status may indicate whether the corresponding fault has been confirmed by the diagnostic programs. When certain diagnostic codes are generated, the control modules may illuminate a warning light on an information display of the vehicle, such as a “Check Engine” light. Similarly, when certain diagnostic codes obtain a particular fault status, the control modules may illuminate the warning light.
On many vehicles, a service tool may be used to diagnose and repair problems with the vehicle. The service tool may be used to access and retrieve the diagnostic trouble codes stored in memory. Typically, the service tool communicates with one or more of the control modules to retrieve the stored diagnostic trouble codes. The diagnostic trouble codes may then be used in conjunction with the vehicle's service manual and other service procedures to determine which driver interface devices, sensors, and actuators should be tested to fully diagnose the problem. The service tool may also be used to modify or clear the diagnostic trouble codes and related fault status stored in memory.